1. Field of the Invention
The present invention relates in general to vehicle seats and more particularly to an adjustable vehicle seat mounting of the kind provided with a stay for supporting a buckle of a seat belt fastener.
2. Description of the Prior Art
A vehicle seat such as a vehicle front seat is mounted on a vehicle body by way of an adjustable seat mounting device so that it can be selectively locked in various adjusted positions relative to a fixed portion of the vehicle. A kind of adjustable seat mounting device is provided with a stay for supporting a buckle of a seat belt fastener. This kind of adjustable seat mounting device is disclosed in Japanese Provisional Utility Model Publication No. 60.137632 and also shown in FIGS. 4 and 5. FIGS. 4 and 5 show a portion of the adjustable seat mounting device disposed on the lower, inboard side of a vehicle seat. The inboard portion of the adjustable seat mounting device includes a stay 10, a lower slide member 12 enlongated in the fore and aft direction of the vehicle body and secured to the vehicle body by way of the stay 10 and an upper slide member 14 slidably mounted on the lower slide member 12 and adapted for mounting thereon a seat cushion. A lock plate 16 is disposed right under the lower slide member 12 and has at the inboard end thereof a number of teeth 18. Secured to an upper, rearward portion of the upper slide member 14 is a stay 20 for supporting a buckle 22 of a seat belt fastener. Secured to a nearly central portion of the stay 20 is a bracket 24 for supporting a release lever 26 which is manually operated when the seat is to be adjusted in position in the fore and aft direction of the vehicle body. Interposed between the release lever 26 and bracket 24 is a return spring 28 for urging the release lever 26 to turn in the direction of the arrow "A". A catch plate 30 is mounted on the release lever 26 for oscilation therewith and has a depending wall portion 30a which is formed with a plurality of holes 32 arranged at the same intervals as the teeth 18 of the lock plate 16 so that the teeth 18 are respectively engageable in the corresponding holes 32 of the catch plate 30.
In the event of a vehicle collision, a force "F" as large as about 100 kg will be applied to the buckle 22 of the seat belt fastener and transmitted therefrom to the vehicle body via the stay 20, bracket 24, release lever 26, catch plate 30, lock plate 16 and lower slide member 12. For this reason, in order that the adjustable seat mounting device can withstand a considerably large impact applied thereto from the seat belt and transmit it to the vehicle body in the event of a vehicle collision, it has been necessary for the stay 20; bracket 24, release lever 26, catch plate 30, lock plate 16 and lower slide member 12 to be enlarged in thickness and diameter, causing an obstacle to the reduction of the vehicle weight.